JP2579162B2 - Drive curve correction device for stepping motor in electronic sewing machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a drive curve correction device for a stepping motor in an electronic sewing machine.

(Prior art and its problems) In order to drive two stepping motors with different drive curves by one signal, two programmable timers are required.

Since one microcomputer can process only one interrupt, the interrupt being processed earlier ends when two programmable timer interrupts occur at the same time, or when another interrupt occurs during interrupt processing. The other has to wait until you do.

For this reason, the stepping motor does not drive according to the set driving curve, so that the vibration at the time of stoppage becomes large or it is easy to lose synchronization.

(Means for Solving the Problems) In order to know what data is input to the programmable timer, a timer buffer is provided and the data is also input to the timer buffer. Further, by comparing the value of the programmable timer with the value of the timer buffer and correcting the time delay, the stepping motor is driven with a drive curve set as desired.

(Example) The present invention will be described with reference to the drawings.

In FIG. 1, an upper-axis synchronization signal 1 that generates a signal once in the upper-axis rotation of the sewing machine (hereinafter, a signal is a pulse-like signal unless otherwise specified) becomes a drivable phase of the stepping motor 16. A signal is given to the pattern data extracting device 2. The pattern data extracting device 2 that detects the rising edge of the signal extracts the pattern data from the pattern data storage device 5. The rotation direction of the stepping motor 16 is set by the rotation direction setting device 6 from the extracted pattern data. Further, the number of moving steps of the stepping motor 16 is set by the moving step number setting device 3 from the pattern data. The information on the rotation direction set by the rotation direction setting device 6 is given to the excitation data setting device 9 of the stepping motor 16, and the information on the number of moving steps set by the moving step number setting device 3 moves the stepping motor 16 by one step. It is sent to a counter 17 which is decremented by one each time.
The moving step number setting device 3 sends a signal to the interrupt preparation device 4. If the content of the counter 17 is not 0, an H-level signal is output to AND1, 19 and AND2, 20 to enable the underflow signal of the down-count programmable timer 7 with reload that generates the time interval of the driving curve. The interrupt preparation device 4 that has detected the rising edge inputs an appropriate value to the programmable timer 7 and prepares for an interrupt. When the programmable timer 7 underflows and outputs an underflow signal, since the programmable timer 7 has a reload, the value inputted earlier is reloaded and the countdown is started again. The underflow signal via AND1,19 is the excitation data setting device 9, counter 17, discriminator
Output to 10. The excitation data setting device 9 sets the excitation data based on the information of the rotation direction setting device 6, outputs the data to the stepping motor driving device 13 for driving the stepping motor 16, and drives the stepping motor 16 by one step by the stepping motor driving device 13. The counter 17 decrements the number of movement steps by one, and if it is 0, outputs a signal of L level and prohibits the interrupt processing by the underflow signal of the programmable timer 7. The discriminator 10 outputs an L-level signal when another interrupt is currently being processed, and outputs an H-level signal when the other interrupt is not being processed.
L level is detected. If the signal is at the H level, a signal is output to the ANDs 2 and 20, and if the signal is at the L level, the signal waits until the signal goes to the H level. The signals via the ANDs 2 and 20 are supplied to the drive curve data extracting device 15. The drive curve data extracting device 15 that has detected the rising edge extracts drive curve data from the drive curve data storage device 18. Then, the data of the drawn drive curve is input as the value of the next programmable timer 7.

 Conventionally, it is driven by the above interrupt processing.

The present invention is obtained by adding a broken line to the conventional interrupt processing. (FIG. 3) FIG. 2 is a control block diagram of the present invention, and a portion within a broken line is a main element of the present invention. When the phase of the stepping motor becomes drivable by the phase detecting means, the pattern data is extracted from the pattern data storing and extracting means, and the rotation direction and the number of moving steps are set from the extracted pattern data. Next, the time interval of the drive curve is set by the time setting means between the occurrence of the interruption and the next interruption, and the time required for the setting is calculated by the required time calculation means. The result and the drive curve data storage and extraction means are input to the means for reducing the required time from the drive curve data, and the result is output to correct the drive curve data. Input to the time setting means until the interruption.

As shown in FIG. 3, the value inputted to the programmable timer 7 is also inputted to the programmable timer buffer 8 which stores the value. Further, the signals from the ANDs 2 and 20 are also supplied to the subtracters 1 and 11 for calculating the required count number of the programmable timer 7 from the time of occurrence of the interrupt to the current time. The subtracters 1 and 11 which detect the rising edge of the signal output the current programmable timer 7 from the value of the programmable timer buffer 8.
, The required count number is calculated, and the result is output to subtracters 2 and 12 for correcting the data of the driving curve. Subtractor
When the results of the subtractors 1 and 11 and the data of the driving curve extracted by the driving curve data extracting device 15 are input, the results of the subtracters 1 and 11 are subtracted from the driving curve data, Correct the data. Then, the corrected drive curve data is input to the programmable timer 7 and the programmable timer buffer 8.

 This will be further described with reference to the timing chart of FIG.

FIG. 3A shows the timing from the occurrence of an interrupt when the stepping motor 1 and the stepping motor 2 are independently driven to the next interrupt and the timing of the interrupt processing. T1, T2, T3, and T4 are the pulse intervals of the set drive curve, that is, the time from the occurrence of an interrupt to the occurrence of the next interrupt. ti is the time required for interrupt processing. (Timer interrupt) t1, t2, t3, t4 is ti
Is the time for generating T1, T2, T3, and T4.

(B) shows the timing of interrupt generation and interrupt processing when the two stepping motors are simultaneously driven by one signal using a conventional driving method. When the interrupt 1 and the interrupt 2 occur at the same time, the interrupt 2 has to wait until the processing of the interrupt 1 is completed because the interrupt 1 has priority. The waiting time is t _L 1. The place where the waiting time by should be T3 becomes t _L 1 minutes longer T3 '. If the interrupt 2 occurs during the processing of the interrupt 1, the interrupt 2 must wait until the processing of the interrupt 1 is completed. The waiting time is t _L 2. The waiting time becomes T4 'which is longer than t4 by t _L 2 minutes.

In the description in the figure, the time interval of the occurrence of the interrupt is long only for the stepping motor 2, but the time interval of the occurrence of the interrupt is also long for the stepping motor 1 depending on the timing.

(C) shows the timing when the two stepping motors are simultaneously driven by the corrected driving method.

t _L 4 is a waiting time of the interrupt 2 when the interrupts 1 and 2 occur simultaneously (the subtracters 1 and 11 in FIG. 3).
Calculated from the above). t3 'is a value obtained by subtracting the t _L 4 from the time t3 (time calculated by the subtractor 2, 12 in Figure 3). In this way, t is corrected instead of t3
By setting it to 3 ', it becomes T3 according to the setting. t _L 3 is a waiting time of the interrupt 1 when the interrupt 1 occurs during the processing of the interrupt 2. T _L 3 Again from the same t2
Is reduced to a value t2 'to obtain T2 as set.

FIG. 5 shows a drive curve for the stepping motor 2 (the same applies to the stepping motor 1 and is omitted).
3 'becomes T3 settings sense a value obtained by subtracting the t _L 4 from t3.

Since T4 does not change from the time of occurrence of the interrupt to the time of the next interrupt occurrence, it becomes T4 according to the setting.

(Effect) By adding the portion indicated by the broken line as described above, it is possible to correct the drive curve and drive the stepping motor with the set drive curve. As a result, the vibration when the stepping motor stops is reduced, and it is difficult to step out.

Furthermore, when two stepping motors or more stepping motors are simultaneously driven with different drive curves by one signal, correction is made by mutually adding a broken line to each interrupt processing and setting each other. Drive curve.

[Brief description of the drawings]

FIG. 1 is a conventional control block diagram, FIG. 2 is a control block diagram of the present invention, FIG. 3 is a control block diagram of an embodiment, and FIG. 4 is an interrupt generation for driving a stepping motor and an interrupt process. It is a timing chart figure. Fifth
The figure is a diagram of a conventional driving curve and a driving curve of the present invention with respect to a set value. In FIG. 2, reference numerals 8 and 11 denote required time calculating means, and 12 denotes means for subtracting the required time from the driving curve data.

Claims (1)

(57) [Claims] 1. A needle which reciprocates up and down and swings laterally, a first stepping motor for swinging the needle in the lateral direction, and a direction in which the cloth to be sewn swings the needle. A cloth feeder for forming a sewing pattern in cooperation with the needle, a needle position control data for determining a needle drop position of the needle, and a feed control for determining a cloth feed amount of the feeder. A storage device for storing pattern data including data, a storage device for storing the pattern data for driving the first and second stepping motors, and a storage device for storing the pattern data.
And a device for extracting the pattern data from the storage device in order to drive the stepping motor of the first and second stepping motors from the pattern data. , A time value storage means for storing, as time values, drive curves for accelerating and decelerating the first and second stepping motors, respectively, and extracting the time values from the time value storage means. A memory extracting means for driving the first and second stepping motors at predetermined drive curves and at predetermined time intervals, an interrupt generating means for generating an interrupt after the elapse of the time interval, and the interrupt means Interrupts simultaneously after the time intervals of the first and second stepping motors have elapsed. Means for waiting for an interrupt at one of the time intervals when the interrupt is generated, and for starting the interrupt after completion of the interrupt processing at the other time interval; calculating means for calculating a processing time required for the interrupt; Subtracting the calculated value from the one time interval value, and driving means for driving one of the first and second stepping motors using the subtracted value of the subtraction means, and When an interrupt occurs at the other time interval during the processing of the interrupt at the interval, the calculating means calculates the processing time of the interrupt, and the subtracting means calculates the value calculated by the calculating means at the other time interval. The driving means drives the other of the first and second stepping motors with the subtraction value of the subtracting means. Driving curve correction device of a stepping motor in an electronic sewing machine, characterized in Rukoto.